Prepping stained temporary mount - Onion epidermis

Question 1

What is the method?

Answer 1

1. Cut small piece of onion tissue
2. Use forceps to peel inner epidermis from square of scale leaf
3. Use forceps to put epidermal strip onto slide - make sure its flat
4. Add 2 drops of iodine solution + use mounted needle to lower cover slip
5. Use filter paper to remove excess + view under microscope

Question 2

Why do we use the inner epidermis?

Answer 2

Its 1 cell thick + has quite large cells - easier to see

Question 3

What parts of the cell absorb the stain more strongly?

Answer 3

Cell walls + nuclei

Question 4

Why do we use a mounted needle?

Answer 4

To support the cover slip above the slide